Adhesives are widely used in the fields of packaging, bookbinding, plywood, woodworking and the like. For instance, hot-melt adhesives are, after their application, cooled and solidified to provide initial bonding in a short period of time, and they provide significantly good workability and are solvent-free, leading to year-by-year increase of their use amount.
Conventionally, a base polymer of the hot-melt adhesives has been an ethylene⋅vinyl acetate copolymer (EVA). In recent years, polymers with a lower density, for example, ethylene⋅α-olefin copolymers, are used in view of e.g., cost cut (See Patent Literatures 1 and 2, for example).
Patent Literature 1 describes an adhesive using an ethylene⋅α-olefin copolymer, but fails to indicate whether properties such as heat stability of that adhesive are satisfactory or not.
Patent Literature 3 describes an ethylene⋅α-olefin copolymer having less amount of double bond in the polymer, excellent in mechanical properties, in molding processability and thermal stability at the time of mold processing, and in heat aging resistance. This literature indicates that copolymer is applicable to industrial uses including waterproof sheets, tatami mat facings, carpet backing materials, architecture, civil engineering pipes, medicine, daily necessaries and protective films, but fails to indicate whether the copolymer is employable as a material of an adhesive.